A few things,
Firstly, that patent does not apply.
That patent is specifically for producing a consumable material. This means that it is producing a filament that is then consumed.
A more challenging patent would be [
www.google.com]
Which could potentially be challenged by saying that a filament is not a wire. Also, as far as I can tell it hasn't actually been granted patent status. [
patft.uspto.gov]
As for thermal dies, this would be very problematic as you would most likely have a thermal gradient in the print head regardless.
I would think a better option would be a photosensitive die and a light source of some kind that illuminates the entire strand would be better and could switch faster.
However I don't know if such a thing exists and this would require preloading the filament with dies which would be rather expensive.
As for long dwell times in the mixer above, the big problem wouldn't be degradation of the plastic, it would be colours coming out at random times making it a fairly useless device.
